Expansion strap clamp



March 15, 1955 J. LEVINE 2,703,914

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.............. m v i F l||l|| llllllllllllllllllllllllllllllllll wh I United States Patent EXPANSION STRAP CLAMP Julius Levine, Brooklyn, N. Y.

Application January 5, 1951, Serial No. 204,630

3 Claims. (CI. 24-71) The invention here disclosed relates to articles in the nature of wrist bands and the like.

These items usually consist of a strap of leather or other such flexible but substantially inelastic material and some kind of a buckle or fastening by means of which the ends of the strap may be connected and disconnected.

It is the general purpose of this invention to retain the advantages of the leather strap form of band and to provide for its free engagement with or disconnection from the wrist, for example, without the bother of having to connect and disconnect the ends of the strap.

The invention therefore, in fact, is an improvement upon the spring urged expansible strap construction hasically covered in copending patent application Serial No. 22,462, filed April 21, 1948, issued as Patent No. 2,541,706, dated Feb. 13, 1951.

Particular features of the present invention are the provison of a spring hinge form of structure arranged to hold the strap contracted but to permit it to slide freely through the same for purposes of expanding the band and which can be quickly adjusted, as required, to cause the band in its contracted relation to snugly fit the wrist or other part to which the band is applied, covers to conceal the spring hinge portion of the structure and to operate as companion stops to hold the spring hinge tensioned in a properly arched formation, and a novel strap construction properly stiffened and strengthened at the ends where Wear may occur, as at the attachment to a watch or other article, and made flexible in the intermediate portion to comfortably fit the wrist and to slide the more readily through the spring actuated band contracting hinge structure.

Another special feature of the invention is the construction of the strap with selected wear resisting and flexible flexible portions in such a way that it may be struck as by dies or other cutting mechanism, from a large size blank and hence be produced at relatively low cost.

Other desirable objects and features of the invention will appear and are set forth in the following specification.

The drawings accompanying and forming part of the specification illustrate certain present embodiments of the invention but structure may be further modified and changed as regards the immediate illustration, all withm the true intent and broad scope of the invention as hereinafter defined and claimed.

Fig. 1 in the drawings is an end or edge view of one of the new expansion bands as applied to a wrist Watch;

Figs. 2 and 3 are enlarged views of the spring hinge construction as it appears at the inside and at the outside of the band, the latter broken away;

Fig. 4 is a further enlarged longitudinal sectlonal view of the spring hinge construction on substantially the plane of line 4-4 of Fig. 3, with the hinge in the expanded, band contracting position;

Fig. 5 is a similar view showing how tension applied to the band will cause the spring hinge to fold and in so doing to release the strap into the extension of the band;

Fig. 6 is a face view of the blank sheet from WhlCh individual straps are cut, with the covering layer partly stripped at one end and the folded part at that end also partially separated from the main back layer;

Fig. 7 is a longitudinal sectional view of the strap material showing the end portions thicker for wear resistance and the intermediate portion thinned for flexible sliding through the spring hinge member;

2,703,914 Patented Mar. 15, 1955 Figs. 8 and 9 are plan views of two of the finished straps, the first shown of generally the same continuous width and the second shown as having a portion narrowed to operate more freely within the hinge member;

Fig. 10 is a broken longitudinal sectional detail of the strap as it appears on substantially the plane of line 10-10 of Fig. 8;

Fig. 11 is an inside view of the spring hinge as used with the substantially continuous Width strap of Fig. 8;

Fig. 12 is a similar view of the spring hinge as used with the narrowed strap of Fig. 9.

Fig. 1 shows how the invention may be used with a wrist watch, with the ends of the strap 15 made into loops 16 engaged over the bars 17 at opposite sides of the watch 18 and the spring hinge construction positioned and operating on the intermediate portion of the strap between such ends.

Specifically the spring hinge is shown as made up of two open, frame-like leaves 19, 20, pivotally connected together at opposite sides by rivets 21, and one of the leaves, 20, having a cross pin 22 at the outer side of the pivot axis 21, carrying a coiled spring 23 having the opposite ends of the same extended and engaged at 24, 25, against the backs or inner sides of the transverse covering portions 26, 27, of the hinge frame or leaves 19, 20.

The cover portion 27 on the hinge leaf or leaves 20 which carries the coil spring, is shown as extended in the form of a loop or arch 28 about the spring, and the end of this arched cover portion is shown in Fig. 4 as engageable with the outer surface of the cover 26 on the opposite hinge leaf to operate as a stop limiting the straightening out movement of the two leaves effected by the spring tension.

The companion cover elements 26, 27, thus serve, as will be clear from Figs. 4 and 5, as coacting stops to limit the hinge leaves to a partly straightened, somewhat arched relation, such as will closely but comfortably fit the wrist of the wearer.

The strap is shown threaded through the spring hinge, substantially the same as in the patent identified, with portions of the strap at opposite sides of the hinge both secured to the same hinge leaf and one of said strap sections doubled and slidingly looped over a bar on the other hinge leaf, so that pull on the strap sections at opposite sides of the hinge will have the effect of collapsing the hinge, as shown in Fig. 5, to release the doubled portion into the encircling band, thus to add to and increase the circumferential extent of the band.

In the present disclosure the two sections of strap at opposite sides of the hinge construction are both secured to the one hinge leaf, 20, by looping the strap at 29, Figs. 4 and 5, and securing this loop in a clarnpmade up of companion jaws 30, 31, pivoted together and pivoted between the sides of the hinge leaf 20 by the cross pin 32.

The clamp jaw 31, as shown in Fig. 5, operates as a toggle to secure the doubled section of strap against the companion jaw 30, and is provided with a leverage extension 33 which may be used as a handle, as shown in the ing of the strap, as required, to fit the band to the wrist with as much firmness or snugness as the wearer may desire.

The clamp construction described provides for continuously variable increments of adjustment, enabling a user to fit the band exactly as wished, and the rocking mounting enables the clamp itself to lay closely against the wrist as in the Fig. 4 position, and to pivot as required, under the pull of the strap, as shown in Fig. 5.

The portion of strap at the left in Figs. 1, 2 and 4, which by means of the clamp connects directly with the end of the far hinge leaf 20, is shown as guided through a confining loop 34 pivoted on a pin 35 secured across the free end of the hinge leaf 19.

The doubled portion of strap at the right hand side, conneceted by the clamp with the end of the same leaf 20, is extended in the form of a loop 36 about the cross bar or pin 35 at the end of leaf 19 so as to operate with pulley elfect to bring the leaves together from the Fig. 4 to the Fig. 5 position.

By the combination of direct pull on hinge leaf or lever 20, from the strap at the left hand side, Fig. 5, and the doubled pulley eflect on this same leaf from the strap at the right hand side, a high degree of lengthening and shortening effect is obtained in a spring hinge construction of relatively small size.

The hinge spring 23, as shown in Figs. 4 and 5, is offset to the outside of the three layers of strap and 30 does not in any way interfere with or impede the hinge movement or the lengthening and shortening of the strap. The spring in this relation also exerts a toggle effect on the hinge levers in the straightening movement of these levers from the Fig. 5 to the Fig. 4 position, tending the more to hold the levers firmly in the band shortening position, Fig. 4.

To provide the greatest wearing comfort and freedom of action in expanding and contracting, the strap is preferably made as flexible as possible, consistent with strength, in the intermediate portion which operates through the spring hinge, and thicker at the ends, to resist wear, where it is connected with the watch or possibly other article.

Fig. 7 shows how the strap may be made up out of a base layer 37, skived and thinned at the extreme ends at 38, and in the long intermediate portion at 39, leaving, near the ends, the thicker, pad portions 40.

The thicker portions, 40, as shown in Fig. 10, are turned over to form the watch bar loops 16, and the thinned, tapered ends 33 secured as by adhesive.

After this a thin, smooth, flexible inner layer 41 may be secured by adhesive and stitching 42 over the inturned and flattened down end loops and over the thinned, flexible, intermediate portion 39 of the back to form a substantially integral strip having stiflened and reinforced end loops connected by a soft, smooth, flexible, intermediate. wrist encircling portion.

The stitching 42, as shown in Figs. 8 and 9, may be extended around all four edges of the finished strap.

This construction of varied thickness strap for use in the band extending and contracting spring hinge, is Well adapted for manufacture in the sheet form illnsrated in Fig. 6, which shows how the two layers, the thinned-inpart back layer 37 and cover layer 41, may, after the loop forming ends of the back layer are turned in and the cover layer then adhesively secured, be cut by suitable dies into the strap forms shown in Figs. 8 and 9.

Fig. 8 shows how the straps may be blanked out with a slight taper in width in the intermediate portion to increase the flexibility and comfort of this portion of the band in fitting the wrist.

Fig. 9 shows how that intermediate looped portion of the strap which is doubled and gripped in the clamp 30, 31, may be narrowed as at 43 to slide the more freely through the clamp jaws.

Fig. 11 shows how a straight edged or slightly tapered intermediate portion of strap is adjustably held in the clamp 30, 31, and Fig. 12 shows how the strap with the narrowed intermediate width portion 43 fits between the hinge leaves and is adjustably held in the clamp.

While particularly for leather or hands of like flexible, substantially inelastic material, it will be realized that the invention may be used with other materials and that the term leather is employed in a descriptive rather than in a limiting sense. Leather-like materials, in addition to their flexibility and non-stretchability, have a free sliding action, one layer over the other, especially desirable in a construction like that shown in Figs. 4 and 5, where the inner of the two layers secured in the clamp must slide through the confining loop 34 at the free end of one lever 19 and the other layer must slide about the bar 35 on that lever as a pulley, over the clamp and, in effect, confined between the clamp at the inside and the overstanding guard or cover 27 at the outside.

What is claimed is:

1. Adjustable expansion band comprising a strap of flexible, substantially inelastic material and a spring hinge of pivotally connected levers having a spring urging said levers into extended, substantially straightened relation, said means consisting of a continuously variable strap holding clamp on the free end of one of said levers, said levers having a cross bar and a confining loop at the free end of the same, said strap having a doubled portion adjustably gripped in said clamp and one layer of the strap extending from the gripped loop through said confining loop on the other lever and the other layer being looped over said cross bar on said other lever and extended back over the clamped loop of strap, said clamp being composed of companion clamp jaws pivotally secured on the free end of the lever so as to be free for swinging movements under the pull of the strap against the hinge levers.

2. The herein disclosed improvements for an expansible band construction having a strap of flexible, substantially inelastic material and a spring hinge of pivotally connected levers having a spring urging said levers into extended, substantially straightened relation, said improvements comprising a mounting pin for the spring on one of said levers and independent of the pivotal connection between the levers, the pivotal connection between the levers comprising rivets disposed at the side edges of the strap and permitting the pivotally connected ends of the levers to move freely past the side edges of the strap, the spring mounting pin being disposed outwardly of said rivets and clear of the strap, said levers having covering portions adjoining the pivotally connected ends of the levers positioned to cover the strap and abutting in the straightening movement of the levers to limit the turning movement and to form a closed cover over the spring, the mounting pin and the rivets connecting the levers.

3. The herein disclosed improvements for an extensible band construction having a flexible strap of substantially inelastic material, a spring hinge having pivotally connected levers and a spring for extending the same into substantially straightened relation, said improvements comprising said hinge levers having substantially parallel side bars spaced apart to operate freely at the edges of the flexible strap, rivets pivotally connecting the side bars of the two levers, said rivets being clear of the edges of the strap to permit free hinging action of the two hinge levers, a pin connecting the opposite side bars of one of said hinge levers disposed outwardly of the rivets and extending across the flexible strap, said spring being disposed about said pin, cross bars connecting the side bars of said lever and said strap having portions connected with a cross bar on one of said levers and looped about a cross bar on the other of said levers and disposed inwardly of the pin on which the spring is engaged and covering portions connecting the side bars of the levers and extending over said pin and spring and abutting in the straightening movement of the levers.

References Cited in the file of this patent UNITED STATES PATENTS 871,144 Reinhard Nov. 19, 1907 1,079,080 Ward Nov. 18, 1913 1,083,678 Fryett Jan. 6, 1914 2,079,711 Johnson et a1. May 11, 1937 2,513,782 Berkeley July 4, 1950 2,541,706 Levine Feb. 13, 1951 2,563,818 Clendening Aug. 14, 1951 OTHER REFERENCES 818,312 France Iune.14, 1937 979,520 France Dec. 13, 1950 

